The tropical Cribellate Orb Weaver spins a very fine silk web that uses design, not substance, to tangle its prey.

The legs of the Cribellate Orb Weaver have flared, feathery tufts of hair at the 'ankles'. The front pairs of legs are extremely long. Oftentimes these front legs are stretched out in front of the spider, grouped next to each other. This position elongates the spider while it sits on its web. Two bumps at the top of the abdomen help disguise the brown and white speckled abdomen.

Webs are built flat and parallel to the ground, at or around knee-height. The spider sits on it, or near it, in its tucked position. Sometimes it lies in wait on the underside of the web, giving it the appearance of a dead flower or piece of leaf. The Cribellate Orb Weaver creates a web that lacks sticky silk. The web itself has tiny gaps between the strands that easily catch the legs of insects landing on it. Small prey get easily tangled, rendering sticky silk unnecessary. The cribellum on the legs allow the spider to 'comb' its web, keeping the fine strands separated until prey enters.

This tiny spider is found in humid, tropical climates and is one of the only spiders that lacks venom. Instead of chemically immobilizing their prey, Cribellate Orb Weavers kill their victims by winding them tightly in silk, squeezing them to death.

Basic Information

Common Name: Cribellate Orb Weaver

Other Name(s): Feather-legged Orb Weaver

Scientific Name:Uloborus spp.

Category: Spider

General Identification

Size (Adult; Length): 3mm to 7mm (0.12in to 0.27in)

Identifying Colors: brown; tan; white

Additional Descriptors: long, tucked, silk

Taxonomic Hierarchy

Kingdom:Animalia

Phylum:Arthropoda

Class:Arachnida

Order:Araneae

Family:Uloboridae

Genus:Uloborus

Species:spp.

Spider Anatomy (Typical)

1

Legs: Spiders have four pairs of legs and these are attached to the cephalothorax.

2

Pedipalps: Small appendages near the mouth used as taste and smell organs.

3

Cephalothorax: Contains eyes, head, mouthparts, and legs.

4

Abdomen: Contains various organs related to digestion, reproduction, and web-making.

5

Spinnerets: Used in the production of spider silk for fashioning webs or catching prey.

NOTE: Unlike insects, spiders have both an endoskeleton (internal) and exoskeleton (external).

Territorial Reach (A-to-Z)

Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed below as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections below indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.

The map below showcases (in red) the states and territories of North America where the Cribellate Orb Weaver may be found (but is not limited to). This sort of data can be useful in seeing concentrations of a particular species over the continent as well as revealing possible migratory patterns over a species' given lifespan. Some species are naturally confined by environment, weather, mating habits, food resources and the like while others see widespread expansion across most, or all, of North America.